Patent GB-788560-A (GB)
Title: Improvements in or relating to plastisol compositions
IPC: C09D157/00
Filed: 1955-06-20
Abstract: Plastisols are made by mixing in aqueous media a water-insoluble non-electrolyte polymer of one or more ethylenically unsaturated monomers in particulate form and an aqueous gel-forming, cross-linked polyelectrolyte polymer containing 1,2-epoxy groups and at least 0.2 acidic groups per 100 molecular weight, simultaneously separating the mixed polymers from the aqueous medium, drying the mixed polymers, e.g. by spray drying, and dispersing the particulate mixture in an organic liquid plasticizer which is a non-solvent for the nonelectrolyte polymer at room temperature but a solvent at elevated temperature. Prior to drying the aqueous polymer dispersion may be mixed with polyvalent salts.  The gel-forming polymer may be obtained by copolymerizing unsaturated acidic monomers with unsaturated epoxy monomers, e.g. methacrylic acid with glycidyl methacrylate or by reacting the acidic groups of a water-soluble polymer with a compound capable of introducing 1,2-epoxide groups.  The polymer containing acidic groups may be the homopolymers of acrylic acid, methacrylic acid, ethacrylic acid, or alphachloroacrylic acid, copolymers of methacrylic acid with methyl methacrylate, vinyl acetate, styrene, or 1,3-butadiene, copolymers of acrylic acid with acrylonitrile, copolymers of maleic acid with ethylene, propylene, isobutylene, styrene, methylvinyl ether, vinyl acetate, vinyl chloride, or ethyl acrylate, polyvinylsulphonic acid, polyvinylbenzenesulphonic acid, polyvinylnaphthalene sulphonic acid, the reaction product of phosphoric acid with polyvinyl alcohol or the hydrolysed copolymers of ethylene-vinyl acetate, lignic acid, alginic acid or carboxymethyl cellulose.  The compounds capable of introducing epoxy groups into the polymers containing acidic groups are preferably haloepoxy compounds such as epichlorohydrin, or hydroxyepoxy compounds.  The acidic polymers are generally reacted with the epoxy compound in the form of their ammonium or alkali metal salts.  Suitable hydroxyepoxy compounds are 2,3-epoxy propanol, 5,6-epoxyhexanol-2, beta-hydroxyethyl ethylene oxide, 3,4 - epoxy - 2,2,4 - trimethylpentanol - 3, epoxydodecanol, epoxy-octadecanol, 3-hydroxy-1,2 - epoxycyclohexane, and alpha - hydroxymethyl - alpha - phenylethylene oxide.  The reaction product of the sodium salt of polyacrylic acid and epichlorohydrin is the exemplified cross-linked polymer.  The water-insoluble polymer may be a homopolymer or copolymer of vinyl fluoride, chloride, bromide, or iodide, 1,1 - dichloroethylene, 1,1 - dichloro - 2,2 - difluoroethylene, trifluorochloroethylene, vinyl formate, vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl laurate, vinyl formal, vinyl acetal or vinyl butyral.  Plasticizers mentioned are tricresyl phosphate, octyl diphenyl phosphate, di-(butoxyethyl) phthalate, dioctyl phthalate, dicapryl phthalate, dibutyl phthalate, methoxyethyl acetyl ricinoleate, and di(butoxy ethyl) sebacate.  The plasticizer may be mixed with a volatile diluent such naphtha or ethyl alcohol.  Polyvalent metal salts mentioned are barium, calcium, magnesium, zinc, mercuric, and aluminium chlorides, tin tetrachloride, cadmium acetate, lead nitrate, nickel diacetate, aluminium potassium sulphate, basic chromium sulphate, sodium silicate, sodium cobaltinitrite, and sodium platinate.  The plastisols may be used for coating and impregnating fabrics and webs of natural and synthetic fibres. The treated fabrics have a leather-like texture, are impermeable to watervapour and liquid water, and exhibit anti-static properties.  The plastisols may also be made into self-supporting films which can be used as food wrappings or ion-exchange membranes, or made into fibres and filaments.  The compositions may also be used as electrical potting compounds, or made into fuel-resistant gaskets or diaphragms.